Answer 10 exam style questions on circulatory system and blood for the NHA CPT exam, each with the correct answer and why every wrong option is wrong.
Start the 10 questions →What prevents blood from flowing backward in the veins of the arms and legs?
These questions cover vessel structure, vessel types, capillary puncture, hemostasis and anticoagulants. Each one shows the correct answer and why every other option is wrong, so a miss tells you exactly what to review before the NHA CPT.
Prefer to read first? Every question from the practice set above, with the correct answer and why each wrong option is wrong.
Answer: A. Veins have one-way valves that keep blood moving toward the heart. Valves can sometimes be felt as small knots and are avoided as puncture sites.
Why not B: Platelets do not line vessel walls.
Why not C: Veins have thinner walls than arteries.
Why not D: Arterial pressure does not stop backflow in veins.
Exam tactic: Veins have valves.
Answer: A. Arteries carry blood under high pressure and have thick, muscular, elastic walls.
Why not B: Capillary walls are one cell thick.
Why not C: Veins have thinner walls and lower pressure.
Why not D: Venules are small, thin-walled veins.
Exam tactic: High pressure, thick walls: arteries.
Answer: D. Warming, for example with a warm compress up to about 42°C for a few minutes, increases arterial flow to the site and makes collection easier.
Why not A: Identification is always required.
Why not B: Heat at this level does not sterilize.
Why not C: Warming does not affect clotting in the container.
Exam tactic: Warm site, better flow.
Answer: C. Fibrinolysis is the breakdown of fibrin clots once the vessel has healed.
Why not A: Hematopoiesis is blood cell production.
Why not B: Vasoconstriction narrows the vessel.
Why not D: Coagulation forms the clot.
Exam tactic: Fibrinolysis = clot removal.
Answer: D. Heparin works with antithrombin to inhibit thrombin and other clotting factors, rather than by binding calcium.
Why not A: It does not remove cells.
Why not B: It prevents clotting instead of breaking clots down.
Why not C: Calcium binding is how EDTA and citrate work.
Exam tactic: Heparin = antithrombin/thrombin.
Answer: C. Red blood cells circulate for about 120 days before being removed by the spleen and liver.
Why not A: No blood cell lives for years in circulation; red cells wear out and are removed after about 4 months.
Why not B: 12 hours is closer to how long a neutrophil circulates; red cells last about 120 days.
Why not D: 3 days is far too short; platelets live about 7 to 10 days and red cells about 120 days.
Exam tactic: RBC lifespan: about 120 days.
Answer: D. An average adult has about 5 liters of blood, roughly 70 mL per kg of body weight.
Why not A: 500 mL is about one donated unit.
Why not B: 1 liter is roughly the blood volume of a 12 to 14 kg toddler, not an adult.
Why not C: 12 liters is more than twice normal; at about 70 mL/kg an adult would need to weigh about 170 kg.
Exam tactic: Adult: about 5 liters.
Answer: A. Hematocrit is the percentage of whole blood volume occupied by packed red cells.
Why not B: White cells are counted in the WBC count.
Why not C: Glucose is a chemistry test.
Why not D: Clotting time is a coagulation measure.
Exam tactic: Hematocrit: percent red cells.
Answer: C. The left ventricle pumps blood to the whole body through the aorta, so it has the thickest muscular wall.
Why not A: The right atrium receives blood from the body.
Why not B: The right ventricle pumps to the lungs at lower pressure.
Why not D: The left atrium receives blood from the lungs.
Exam tactic: Left ventricle: the strongest pump.
Answer: A. Capillary walls are one cell thick, which allows gases, nutrients and wastes to pass between blood and tissue.
Why not B: Artery walls are too thick for exchange.
Why not C: Veins return blood to the heart.
Why not D: Valves control direction of flow.
Exam tactic: Exchange happens in capillaries.
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